Delayed infection?!?!?!?

I have an IPA that I kegged 11/25/07 and have been slowly drinking since. I had a pint a couple of days ago, and noticed the malt flavor had intensified. Today, it is undrinkable! The keg has not been opened at all, and the gas has been on it throughout.

This is the only beer I have ever brewed that didn't clear, even though it sat in prim/sec for close to 2 months, however, it tasted pretty good out of the keg for almost 2 months!

Any ideas?

Thanks.

Infections that sour beer can take months to develop.

When you say malt flavor be more specific. I know hop flavor and aroma can fade over time which would increase your perception of the malt but this sounds much more intense.

RichBrewer said:

When you say malt flavor be more specific. I know hop flavor and aroma can fade over time which would increase your perception of the malt but this sounds much more intense.

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I'm not sure how else to describe other than to say that at first, yes, I thought maybe the malt profile was more predominant as the hop bitterness and aroma faded. However, several days later, it definately has a very strong musty flavor that has overwhelmed the beer.

I guess I just wanted to know (asside from sourness), can spoiling bacteria really take 2 months to destroy a brew? The only other possibilty I could think of is that maybe something weasled it's way in through the gas post when I was switching around my CO2 lines? is that possible, and can an infection move from keg to keg through the CO2 lines?

I have not had any beer get sucked back up into the gas lines at any point.

Thanks.